1. Field of the Invention
The present invention relates to a seat belt alarm apparatus for prompting to fasten a seat belt, particularly to a warning system for a passenger about an unbuckling condition of the seat belt without giving the passenger an uncomfortable feeling.
2. Description Related Art Statement
Heretofore, in this type of seat belt alarm apparatuses, occupants including a driver are prompted to fasten seat belts by driving a buzzer and an alarm lamp when an ignition switch is turned on and a seat belt is unfastened.
For example, Japanese Unexamined Patent Application Publication No. 11-342831 discloses a technology for prompting the occupants to fasten the seat belts when the seat belt is unfastened while a vehicle travels by lighting the alarm lamp as well as interrupting a power supply to an audio device and an air conditioner.
In the technology disclosed in Japanese Unexamined Patent Application Publication No. 11-342831, however, when the vehicle starts in a state that the seat belt is unfastened, since the audio device and the air conditioner are instantly stopped, the driver, who does not sufficiently recognizes that a seat belt alarm is issued, is liable to make misunderstanding that these are stopped by malfunction, which gives incomprehensible or uncomfortable feeling to the driver.
Further, comfortable environment presenting means such as the audio device, the air conditioner, and the like is arbitrarily manipulated by the occupants, when all of these are turned off from the beginning, an environment in the vehicle when the vehicle stops is not changed from an environment when the vehicle starts. Accordingly, it is impossible to raise awareness of the occupants for fastening the seat belt. Further, even if the comfortable environment presenting means are turned on while the vehicle travels, the occupants make misunderstanding that a failure occurs in them, which gives incomprehensible feeling to the occupants since these do not operate when the seat belt is unfastened.